The present invention relates to an improved pulling mechanism of an adhesive-dispensing gun, wherein a push plate is disposed in a gun base to be driven by a trigger to push a push rod forward, and a stopper plate is disposed in the gun barrel to stop the push rod and prevent the same from moving backward, permitting the same to further move forward, whereby when the trigger is released, a torque spring will restore the trigger back to its home position to contact the stopper plate and push the same out of the stopping position so that the push rod can be directly pulled back without biasing the stopper plate with a finger.
A conventional adhesive-dispensing gun is shown in FIG. 1, wherein a push rod 2 extends through a gun base 1 into a gun barrel 3. A push plate 4 is fitted on the push rod 2 between a rear wall 11 of the gun base 1 and a rear wall 31 of the gun barrel 3. A spring 5 is fitted on the push rod 2 between the push plate 4 and the rear wall 31. A pivotable stopper plate 6 is fitted on the push rod 2 behind the rear wall 11. A spring 7 is disposed between the stopper plate 6 and the rear wall 11. A trigger 8 is pivotably disposed in the gun base 1.
As shown in FIG. 2, the push rod 2 is moved forward in such a manner that the trigger 8 is triggered to bias the push plate 4 which further pushes the push rod 2 forward. The moving forward push rod 2 must be prevented from moving rearward by a stopping force while when the trigger 8 is again triggered, the push rod 2 must further move forward. The stopper plate 6 is biased by the spring 7 to be oriented at an angle .theta. with respect to the push rod 6 so as to stop the push rod 2 and prevent the same from moving backward. However, this also makes the adhesive container located in the gun barrel 3 still under a pressurized state by the push rod 2 after the push rod 2 is released. As a result, the adhesive is often further dispensed outside until the pressure disappears. Such further dispensed adhesive is not used and wasted.
As shown in FIG. 3, when the push rod 2 is pushed to the end of the gun barrel, the stopper plate 6 must be pressed by a finger to eliminate the angle .theta. and the stopping force so as to pull back the push rod 2. Such procedure is quite troublesome.